The ubiquitous skid steer vehicle is highly useful vehicle for performing work, especially in relatively confined spaces. The skid steer vehicle is relatively compact and by skid steering, is capable of turning substantially about a vertical axis defined through the skid steer vehicle. Numerous attachments are designed or being designed for use on the skid steer vehicle, including all sorts of earth working attachments, lawn mowers, augers, snow blowers, stump chippers, concrete mixers and the like.
As noted above, the skid steer vehicle turns by skidding. None of the four wheels of the skid steer vehicle is steerable, but is always in a fixed relationship with respect to the chassis of the skid steer vehicle. Steering is performed by, for example, locking (or backing) the wheels on a first side and driving the wheels on the second side in a forward direction, or locking (reversing) a first track and driving the second track forward. In either case, a pivoting action is induced in the skid steer vehicle with resulting skidding of one or more of the wheels or one track. Such skid steering operation works quite well when the skid steer vehicle is being operated over loose soil or other relatively slippery surfaces. A problem arises when the skid steer vehicle is operated on a hard, dry, non-slippery surface such as asphalt or concrete, especially when the load being borne by the skid steer vehicle 20 causes generally equal weight distribution on the front and rear axles.
Skid steering on a hard, non-slippery surface rapidly wears down the tread of the tires (tracks) on the skid steer vehicle. Additionally, with the significantly greater resistance generated between the wheels and the hard surface, large side loads are imposed on the wheels and substantial powers demanded of the skid steer vehicle in order to effect the pivoting, skidding type steering. Accordingly, there is a need in the industry for providing a reduced amount of skidding of the skid steer vehicle when operated on hard surfaces. Advantageously, the device that performs this function should be semi-permanently mounted to the skid steer vehicle, generally within the existing envelope (footprint) of the skid steer vehicle, and convenient to operate. The envelope or footprint of the skid steer vehicle is the outline of the image projected on an underlying surface by the skid steer vehicle when viewed from above.
When performing work with the skid steer vehicle in a fixed location, such as backhoe operations, chipper/shredder, stump grinding, concrete mixing, and the like, the skid steer vehicle may undesirably bounce in a front to rear manner, or may actually tip rearward. There is a need to stabilize the rear of the skid steer vehicle during such operations.
Since skid steer vehicles are utilized in relatively limited spaces, it is desirable that any devices for meeting the aforementioned needs be limited in size and fall substantially within the existing footprint or envelope of the skid steer vehicle, both laterally and rearward. Additionally, virtually all makes of skid steer vehicles have a rear engine access door. This access door is typically hinged at one side and is opened relatively frequently for servicing of the engine of the skid steer vehicle. Accordingly, any device for meeting the aforementioned needs should not impair the ability to open the rear engine access door and should not substantially increase the footprint of the skid steer vehicle. And, the device should project laterally from the respective left and right side margins of the skid steer vehicle less than the rearmost driving element. Further, the device should not impair the approach angle of the skid steer vehicle when the device is in the retracted, non-engaged disposition.